Crawler mounted rock drill



Nov. 18, 1969 R. w. HUGHES ET AL 3,478,532

CRAWLER MOUNTED ROCK DRILL Filed Oct. 27. 1967 INVENTORS ROBERT W HUGHES FRANCIS R COYNE BY? v 3 v ATTORNEY United States Patent 3,478,832 CRAWLER MOUNTED ROCK DRILL Robert W. Hughes and Francis P. Coyne, Easton, Pa.,

assignors to Ingersoll-Rand Company, New York, N.

a corporation of New Jersey Filed Oct. 27, 1967, Ser. No. 678,566 Int. Cl. B62d 55/00 US. Cl. 1809.6 6 Claims ABSTRACT OF THE DISCLOSURE A rock drill mounting of the crawler type which includes a pair of parallel, spaced apart crawler assemblies. These is a deck pivotally mounted at the rear of each crawler. A beam is mounted on the inside of the forward end of each crawler and extends inwardly and rearwardly. The rear end of each of these beams is pivotally connected to the frame. A cross bar is pivotally connected to the forward end of the deck. A torsion bar is connected between the beams so that as one of the crawlers is raised or lowered relative to the other, some of the energy induced by this movement is stored by the torsion bar.

BACKGROUND OF THE INVENTION This invention relates to mountings for rock drills and more particularly to a crawler mounting which is well adapted for use where the terrain is rough.

Many present crawler mountings for rock drills consist of a pair of articulated crawler assemblies with a deck pivotally mounted to the crawler assemblies. As the vehicle traverses rough terrain, one of the crawler assemblies may move in a vertical plane relative to the other crawler assembly so that the vehicle can move over an obstruction in its path such as a rock. The vertical movement of the crawler assembly is transferred through linkages to produce an equal but opposite displacement of the other crawler assembly. The deck on which the rock drilling apparatus is supported remains generally level. In such mountings, the energy produced by the action of the crawler assemblies is imparted to the vehicle and the rock drilling apparatus This tends to result in a generally unstable apparatus which may cause damage to the drilling apparatus through improper alignment.

Although various spring arrangements have been tried, such apparatus has not been successful. Spring arrangements usually involve large displacement so that the restoring force feeds large forces back into the system and the arrangement loses its effectiveness. Other attempts to stabilize the vehicle by absorbing a portion of the energy produced by the action of the crawlers have resulted in complex systems whose disadvantages outweigh their advantages.

SUMMARY It is therefore the principal object of this invention to provide apparatus of' simple construction for stabilizing a crawler mounted drill support.

It is another object of this invention to provide ap paratus which reduces the amount of energy induced in the vehicle by the movement of the articulated crawler assemblies. v

It is a further object of this invention to provide energy storage apparatus for use with crawler type vehicles which will not impart large accelerating forces to the vehicle due to the restoration of the energy absorbing apparatus.

In general these objects are carried out by providing a rock drill support which comprises 'a pair of parallel spaced apart crawler assemblies. A pair of beams each have one end mounted forwardly on the inside of each 3,478,832 Patented Nov. 18, 1969 cross bar to the energy storage means.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects will become apparent from the following description and drawings wherein:

FIG. 1 is a side view of a crawler mounted drilling machine made in accordance with this invention; 2 is a top plan view of one embodiment of this invention;

FIG. 3 is a front elevational view of the drill support of FIG. 2;

FIG. 4 is a sectional view taken on the line 44 of FIG. 3 looking in the direction of the arrows;

FIG. 5 is a sectional view taken on the line 55 of FIG. 4; and

FIG. 6 is a fragmentary view taken on the line 6-6 of FIG. 3 looking in the direction of the arrows.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 there is shown a crawler type vehicle generally indicated at 1. A boom apparatus generally indicated at 3 is secured to an upwardly extending support 2. A drill guide 4 is mounted on the boom apparatus 3 and supports a drilling machine 5." A drill rod 6 depends from the drilling machine 5 and has a drill bit 7 connected thereto. The details of the boom and drilling machine are well known in the art and a detailed description is not considered necessary. It should be noted, however, that it is important to maintain proper alignment of the boom and drilling machine with the vehicle to insure proper drilling.

The crawler mounting for the present invention is best shown in FIGS. 2 and 3 and includes a pair of spaced apart crawler assemblies 10 and 11. These crawler assemblies are driven by suitable motors such as electric or fluid motors 12 and 13 positioned toward the rear of the crawler assemblies 10 and 11, respectively. The drive mechanism is well known in the art and the details are not shown.

A suitable deck generally indicated at 20 is provided for mounting the support 2 and drilling apparatus on the vehicle. The deck is pivotally connected to the rearward end of each of the crawler assemblies as at 21 and 22. The deck includes a rearwardly extending portion 23 from which depend a pair of trunnions 24 and 25. The forward end of the deck 20 is provided with a suitable trunnion 27 on which is rotatably mounted a suitable cross bar 30 which is made in the form of a yoke. A pair of beams 14 and 15 have one end mounted forwardly and on the inside of each of the crawler assemblies. These beams extend inwardly and rearwardly as is best shown in FIG. 2. At their other ends, the beams 14 and 15 are connected to the trunnions 24 and 25 so that they are pivotally connected to the deck 20.

The cross bar or yoke 30 has pivotally connected thereto a pair of links 31 and 32 as at 33 and 34, respectively. The opposite end of the links 31 and 32 are pivotally connected at 35 and 36 to a pair of clevises 37 and 38. Each of these clevises is connected to one of the beams 14 and 15 and is provided with a suitable socket 39 in the form of a polygon. In the present embodiment this has been shown as a rectangle (FIGS. 4 and 5) although such configuration is not to be a limiting factor.

Energy storage means in the form of a torsion bar 40 having an end with a shape substantially conforming to the shape of socket 39 is received by each of the sockets 39 so that it extends between the clevis 37 and the clevis 38. The depth of the socket 39 is greater than the amount the torsion bar normally extends into the opening. As is readily apparent, the cross bar 30 is pivotally connected to the torsion bar and the beams 14 and 15 through the linkages 31 and 32.

As the machine progresses over the ground and rough terrain is traversed, one of the crawler assemblies may encounter rock formations which necessitates that it moves upward or downward relative to the other crawler assembly. If crawler assembly is moved up to move over a raised portion of the terrain while crawler assembly 11 remains level, beam 14 will pivot about the trunnion 24, and the cross bar 30 will pivot about the trunnion 27 in a clockwise direction and crawler assembly 11 will tend to be moved downward by the movement of the cross bar 30 pivoting about the trunnion 25. As the crawler assembly 10 moves upward pivoting about trunnion 24, the clevis 37 will move through an arc. Because the rectangular opening 39 of the clevis 37 is stationary with respect to the beam 14, it will tend to be rotated out of angular alignment with the opening 39 in the clevis 38 so that the sides of the opening 39 of clevis 37 will be at an angle to the sides of the opening 39 of the clevis 38. Because the bar 40 extends between the two openings 39, this angular misalignment will twist the bar 40 and result in a torque being applied thereto. This twisting does not impair the action of the crawlers. No bending force is applied to the torsion bar 40 because the bar 40 slidably fits in the socket 39 so that as the crawler assembly is raised, the bar 40 moves in the socket 39. Thus, the primary consideration in designing the bar 40 is its energy storing ability.

With prior apparatus of this type, the action of the crawler assemblies produces energy which is transferred to the vehicle and particularly the deck and drill. With the present invention, however, when one of the crawlers is displaced relative to the other, some of this energy is stored by the torsion bar 40 and not transferred to the vehicle. Although other arrangements have been proposed for absorbing this energy and preventing its transfer to the vehicle, the torsion bar is particularly well suited for this purpose. The angular displacement is small so that the restoring force can feed the stored energy back into the system without introducing large accelerating forces. The resisting force is proportional to the displacement.

In order to limit the travel of the articulated crawler assembly to an amount which is consistent with the allowable stress level of the torsion bar 40', a pair of stops 41 and 42 have been provided. As one of the crawler assemblies 10 or 11 are raised relative to the other, the beam 14 or will engage the stop limiting the amount of torque applied to the torsion bar 40 and further movement of the crawler assembly causes the deck to be lifted.

From the foregoing it is apparent that the objects of this invention have been carried out. We have provided Cir a simple arrangement for attenuating the energy imparted to the vehicle by the action of the crawlers. The apparatus includes no moving parts and is readily serviceable should breakdowns occur.

We claim:

1. A rock drill support comprising:

a pair of parallel, spaced apart crawler assemblies;

a pair of beams each having one end mounted forwardly on the inside of one of said crawler assemblies and extending rearwardly and inwardly therefrom;

a deck pivotally connected to the rear portion of each of said crawler assemblies. and pivotally connected to the other end of said beams;

a cross bar pivotally connected to said deck;

a separate torsion bar extending between said beams;

means mounted on said beams for connecting the ends of said torsion bar to said beams whereby a torque is applied to said torsion bar when one of said crawlers moves relative to the other of said crawler assemblies in a substantially vertical plane; and

means pivotally connecting end portion of said cross bar to said means connecting the ends of said torsion bar to said beams.

2. The drill support of claim 1 wherein said means pivotally connecting said cross bar to said energy storing means includes a pair of links; one end of each of said links pivotally connected to one end of said connecting bar and the other end of each of said links being pivotally connected to said means connecting said torsion bar to said beam.

3. The drill support of claim 2 wherein said torsion bar is longitudinally moveable relative to said beams.

4. The drill support of claim 3 wherein said means connecting said torsion bar to said beam is a socket having a polygonal opening therein for slidably receiving said torsion bar and said torsion bar has ends with a shape substantially conforming to said opening.

5. The drill support of claim 4 further comprising means for limiting the amount of torque applied to said torsion bar.

6. The drill support of claim 1 wherein said means connecting said cross bar to said beams includes a clevis mounted on each of said beams, a link having one end pivotally connected to said clevis and the other end pivotally connected to said cross bar.

References Cited UNITED STATES PATENTS 2,828,137 3/1958 Wagner ISO-9.5 2,948,347 8/1960 Risk --9.5 3,177,961 4/1965 Potter 1809.5 3,225,849 12/1965 La Casse 180-95 FOREIGN PATENTS 867,359 2/ 1953 Germany.

RICHARD J. JOHNSON, Primary Examiner 

